Glass modification processes available for CVD diamond deposition

Abstract

[Solution] The diamond system includes a glass substrate having a first surface and a second surface, the second surface being chemically modified by ion substitution, and a CVD-deposited diamond layer may be present on the first surface or on an additional surface or edge.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 434,262, filed December 21, 2022, which is incorporated herein by reference in its entirety.

[0002] The present invention generally relates to systems and methods for applying diamond coatings to chemically modified or ionically substituted glass using chemical vapor deposition (CVD). Typically, at least one surface of a transparent glass substrate is chemically modified before or after diamond deposition to increase the hardness and durability of the glass. [Background technology]

[0003] Diamond films or coatings can be used to protect optical systems, for consumer applications such as smartphone or watch displays, for coating tools or machine parts, for chemical protection, or for electrical or semiconductor applications. Advantageously, diamond films offer improved hardness, scratch resistance, and water resistance, as well as a variety of unique electrical properties. However, commercially viable diamond films or coatings remain limited due to the cost and time required to deposit useful thicknesses of diamond coatings on glass substrates.

[0004] Another problem with diamond coatings on glass substrates arises from the CVD heat treatment of chemically modified glasses. To increase durability and reduce the likelihood of cracking, glass can be chemically modified by immersion in a salt bath. For example, glass can be immersed in a potassium nitrate bath at temperatures exceeding 300 °C. Sodium ions present on the glass surface are replaced by potassium ions in the bath. Because potassium ions are larger than sodium ions, the sodium ion replacement creates greater stress on the glass surface, protecting the glass from breakage, scratches, and thermal shock. As another example, aluminosilicate glasses containing aluminum oxide at levels of 20–40% can be treated in molten salt solutions at approximately 400 °C. Again, the smaller sodium ions are exchanged for larger potassium ions, resulting in greater surface strength.

[0005] Unfortunately, reheating chemically modified glasses in a CVD chamber for diamond deposition can cause potassium and other ions to diffuse from the glass surface and throughout the glass, eliminating or reducing the chemical modification of the glass surface. What is needed are glass structures and processing techniques that provide or enable chemically modified glasses with deposited diamond coatings. Summary of the Invention [Means for solving the problem]

[0006] Disclosed herein are new and improved systems and methods for diamond coating using a CVD system. In some embodiments, a diamond-coated glass structure can include a glass substrate having a first surface and a second surface, the second surface being chemically modified by ion substitution. A CVD-deposited diamond layer can be provided on the first surface.

[0007] In some embodiments, the CVD deposited diamond layer has less than 20% SP2 carbon.

[0008] In some embodiments, the CVD deposited diamond layer comprises multiple diamond layers.

[0009] In some embodiments, the CVD deposited diamond layer comprises a layer of ultra-nanocrystalline diamond on a layer of nanocrystalline diamond.

[0010] In some embodiments, the substrate has a dimension of at least 1 centimeter.

[0011] In some embodiments, the ion substitution further comprises replacing at least some of the sodium ions with potassium ions.

[0012] In some embodiments, the ion substitution further comprises replacing at least some of the ions on the second surface to a penetration depth of less than 100 microns.

[0013] In some embodiments, the diamond-coated glass structure can include a glass substrate having a first surface and a second surface, the first surface and the second surface being chemically modified by ion substitution to provide different penetration depths between the first surface and the second surface, and a CVD-deposited diamond layer can be provided on at least one of the first surface and the second surface.

[0014] In some embodiments, the diamond-coated glass structure can include a glass substrate having opposing first and second sides and four edges, wherein the first and second sides and the four edges are chemically modified by ion substitution, and the penetration depth of the first side is different from that of the second side and at least one of the four edges. A CVD-deposited diamond layer can be provided on the first side.

[0015] In some embodiments, a method of manufacturing a diamond-coated glass structure can include providing a glass substrate having a first side and a second side, wherein a diamond layer is CVD deposited on the first side, and wherein the second side is chemically modified by ion substitution after CVD diamond deposition.

[0016] In some embodiments, a method for manufacturing a diamond-coated glass structure can include providing a glass substrate having a first side and a second side. The first side and the second side can be chemically modified by ion substitution. After chemical modification of the first side and the second side, a CVD diamond layer can be deposited on the first side.

[0017] In some embodiments, a method of manufacturing a diamond-coated glass structure can include providing a glass substrate having the first side and the second side.

[0018] The first and second surfaces may be chemically modified a first time by ion substitution, and a diamond layer may be deposited on the first surface by CVD. After CVD diamond deposition, both the first and second surfaces of the glass substrate may be chemically modified a second time by ion substitution. In some embodiments, only the second surface may be chemically modified by ion substitution.

[0019] Other systems, methods, aspects, features, embodiments, and advantages of the systems and methods disclosed herein will become apparent to one of ordinary skill in the art upon examination of the following figures and detailed description, and it is intended that all such additional systems, methods, aspects, features, embodiments, and advantages be included herein and be within the scope of the appended claims. [Brief explanation of the drawings]

[0020] It should be understood that the drawings are for illustrative purposes only. Additionally, the components in the drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the systems disclosed herein. In the drawings, like reference numbers indicate corresponding parts throughout the different views. [Figure 1A] FIG. 1A is an exemplary schematic diagram of a glass substrate that has been diamond coated on one side and then subjected to a chemical modification process on the side or edge that is not diamond coated. [Figure 1B] FIG. 1B is an exemplary schematic diagram of a glass substrate that has been chemically modified and then at least partially coated with diamond. [Figure 1C] FIG. 1C is an exemplary schematic diagram of a glass substrate that has been optionally chemically modified and then at least partially coated with diamond, and further subjected to a chemical modification process on the face or edge already coated with diamond. [Figure 1D] FIG. 1D is an exemplary schematic diagram of a chemically modified glass substrate having opposing upper and lower surfaces and four edges. [Figure 1E] FIG. 1E is an exemplary graph showing the penetration depth of substitutional ions into a glass substrate. [Figure 2A] FIG. 2A is an exemplary block diagram of one embodiment of a method for producing chemically modified glass, such as that shown in FIG. 1A, with one side diamond coated. [Figure 2B] FIG. 2B is an exemplary block diagram of one embodiment of a method for producing chemically modified glass having one side diamond coated, as shown in FIG. 1B. [Figure 2C] FIG. 2C is an exemplary block diagram of one embodiment of a method for producing chemically modified glass having at least one diamond coated surface, as shown in FIG. 1C. DETAILED DESCRIPTION OF THE INVENTION

[0021] In the following detailed description, one or more specific embodiments are described and illustrated by reference to and incorporating the drawings. These embodiments are provided for purposes of illustration and teaching only, and are not intended to be limiting, and have been shown and described in sufficient detail to enable those skilled in the art to practice the claimed subject matter. Thus, for purposes of brevity, these descriptions may omit certain information known to those skilled in the art.

[0022] As used in this disclosure, the terms "layer," "film," and "coated" can be used interchangeably and refer to a thinly deposited, chemically formed growth material or other suitable material on a substrate, which itself can be a layer, film, or coating. A diamond layer or film can comprise intrinsic diamond, diamond-like material, or diamond containing small amounts of graphite or other materials. The lattice structure of diamond can be selectively modified, including varying the sp2 / sp3 carbon material configuration through selective seeding or etching, nucleation or growth process parameters, including, inter alia, parameters such as gas composition, pressure, and temperature, selective laser annealing, particle bombardment or doping, or the use of laser pulses to grow diamond. Further embodiments include modifying the diamond layer or film by oxygen termination, hydrogen termination, or functionalization with chlorine or fluorine.

[0023] The diamond structures and methods of manufacture described herein may incorporate the systems and methods disclosed and described in U.S. Patent Application Publication No. 2013 / 0026492 to Adam Khan, published January 31, 2013; U.S. Patent No. 8,354,290 to Anirudha Sumant et al., published January 15, 2013; U.S. Patent No. 8,933,462 to Adam Khan, published January 13, 2015; U.S. Patent Application Publication No. 2015 / 0206749 to Adam Khan, published July 23, 2015; and U.S. Patent Application Publication No. 2015 / 0295134 to Adam Khan et al., published October 15, 2015, all of which are incorporated herein by reference in their entireties.

[0024] In one embodiment, chemical modification may include subjecting the diamond-coated glass to an ion exchange process. As used herein, the terms "ion exchange" or "ion substitution" are understood to mean that the glass may be chemically modified by an ion exchange process known to those skilled in the art. Such ion exchange processes include, but are not limited to, treating the glass with a solution containing ions with a larger ionic radius than the ions present at the surface of the glass, replacing the smaller ions with larger ions. In one embodiment of this process, at least some of the ions of a first element in the surface region of the glassware are exchanged with ions of a second element, each of which has an ionic radius larger than the ion radius of the replaced ion of the first element. In one embodiment, the first and second elements are alkali metals. Replacing sodium (Na+ ions) with potassium (K+ ions) is a non-limiting example of such an ion exchange. Alternatively, other alkali metal ions with larger atomic radii, such as rubidium or cesium, may replace the smaller alkali metal ions in the glass. In other embodiments, the smaller alkali metal ions may be replaced by silver (Ag+) ions. In some embodiments, additional elements such as Li+, Rb+, Cs+, Cd2+, Zn2+, or Cu+ / Cu2+ may be used. As will be appreciated, ion exchange can occur before or after diamond coating, and multiple ion exchange events may occur during processing of the glass.

[0025] Ion exchange may be performed using methods known in the art and described herein. Depending on the ion penetration depth and other properties, chemical modification of a glass substrate by ion exchange can strengthen, harden, or both the glass. In one embodiment, the glass is immersed in a molten salt bath containing an alkali metal salt, such as potassium nitrate (KNO), for a predetermined period of time to achieve ion exchange. In some embodiments, the glass substrate can be chemically modified in a single ion exchange step. In some embodiments, the glass substrate is immersed in a molten salt bath containing a salt of a larger alkali metal cation. In some embodiments, the molten salt bath comprises, or consists essentially of, a salt of a larger alkali metal cation. In some embodiments, a single ion exchange process may be performed at a temperature below 600°C, while in other embodiments, the temperature may be between 275°C and 550°C for a time sufficient to achieve the desired ion penetration depth (which may increase as the glass thickness increases, and may be between 5 microns and 300 microns in some embodiments).

[0026] In another embodiment, the glass substrate can be chemically modified using a two-step or dual ion exchange process. In the first step of this process embodiment, the glass substrate is ion-exchanged in a first molten salt bath. After the first ion exchange is completed, the glass can be optionally diamond-coated and then immersed in an additional ion exchange bath (e.g., a second ion exchange bath). The additional or second ion exchange bath can have the same composition as the first ion exchange bath. Alternatively, the additional or second ion exchange bath can have a different composition than the first ion exchange bath and / or be operated at a different immersion time and temperature.

[0027] As shown in FIG. 1A, the systems and methods provided herein enable the fabrication of a partially diamond-coated glass structure 100A. The glass structure 100A includes a glass substrate 110A having a first surface 112A, a second surface 114A, and an edge 116A. In one embodiment, the second surface 114A and the edge 116A are chemically modified by ion substitution, resulting in significant substitution to a depth of less than 100 microns along the second surface 114A and the edge 116A, as shown in FIG. 1A as ion-permeated region 120A. Advantageously, the chemical modification of the glass substrate 110A can be performed after deposition of a diamond layer 130A on the first surface 112A. Depending on the ion penetration depth and other properties, the chemical modification of the glass structure by ion substitution can result in strengthening, hardening, or both of the glass.

[0028] In another embodiment, shown in FIG. 1B, the systems and methods provided herein enable the fabrication of a partially diamond-coated glass structure 100B. The glass structure 100B includes a glass substrate 110B having a first side 112B, a second side 114B, and an edge 116B. In one embodiment, the first side 112B, the second side 114B, and the edge 116B are chemically modified by ion substitution, resulting in significant substitution to a depth of less than 100 microns along the first side 112B, the second side 114B, and the edge 116B, as shown in FIG. 1B as ion-permeated region 120B. In this embodiment, the chemical modification of the glass substrate 110B can be performed prior to deposition of a diamond layer 130B on the first side 112B. Due to potential ion migration under the thermal conditions required for diamond deposition, the depth of the ion-permeated region 120B will differ significantly between the first side 112B and the second side 114B. In some embodiments, variations in ion concentration or ion depth in the ion-impregnated region 120B of the second surface 114B can be limited by contacting the second surface 114B with a cooling fixture during diamond deposition.

[0029] FIG. 1C is an exemplary schematic diagram of a glass substrate that has been optionally chemically modified and then at least partially coated with diamond, with a further chemical modification process performed on the diamond-coated surface or edge. The glass structure 100C includes a glass substrate 110C having a first surface 112C, a second surface 114C, and an edge 116C. In one embodiment, the first surface 112C, the second surface 114C, and the edge 116C are chemically modified by ion substitution, resulting in significant substitution to a depth of less than 100 microns along the first surface 112C, the second surface 114V, and the edge 116V, as shown in FIG. 1C as ion-permeated region 120C. In this embodiment, the chemical modification of the glass substrate 110C can be performed prior to deposition of a diamond layer 130C on the first surface 112V. Due to the potential for ion migration under the thermal conditions required for diamond deposition, the depth of the ion-permeated region 120C differs significantly between the first surface 112C and the second surface 114C. In some embodiments, changes in ion concentration or ion depth in the ion-permeated region 120C of the second surface 114C can be limited by contacting the second surface 114C with a cooling fixture during diamond deposition. Alternatively, or in addition, after deposition of the diamond layer 130C, the glass structure 100C can be placed in a second or multiple ion exchange baths for further chemical modification. In some embodiments, chemical modification by dopant implantation through the diamond layer 130C can be used to increase the ion concentration or permeation depth below the diamond layer 130C.

[0030] 1D is an exemplary schematic diagram of a chemically modified glass substrate 110C having opposing top and bottom surfaces and four edges with corners. After ion exchange for chemical modification, the regions between the penetration depth 105D (shown by the dotted lines) and each of the top, bottom, edges, and corners are chemically modified.

[0031] FIG. 1E is an exemplary graph 100E illustrating the penetration depth 105E of replacement ions into a diamond-coated glass substrate as described in FIGS. 1A-D. In one embodiment, the ion exchange results in a penetration depth profile in which the glass is formed with an ion-exchanged surface layer at the top, bottom, or edge of the glass substrate, with a depth of at least 20 microns. In other embodiments, the penetration depth into the glass is at least 5 microns, 10 microns, 20 microns, 30 microns, or 50 microns. As is evident from the graphs and illustrations of FIGS. 1B and 1C, the penetration depth of the ions varies depending on whether or not a diamond layer is present. In this embodiment, the penetration of ions through the diamond-coated top layer is significantly less than the penetration at the edge or bottom.

[0032] FIG. 2A is an exemplary block diagram of one embodiment of a method for fabricating a chemically modified glass substrate structure, as shown in FIG. 1A, having one side coated with diamond. In this embodiment, in a first step 210A, CVD diamond is formed on at least a first side. The first side can be either a top, bottom, edge, or corner. In some embodiments, additional second, third, or other sides can be coated with CVD diamond in addition to the first side. In step 212A, at least a second side of the glass substrate structure is chemically modified using ion substitution. The second side can be either a top, bottom, edge, or corner. In step 214A, one or more processing steps, which can include optional additional laminates (e.g., organic, polymer, inorganic, or graphene coatings), can be applied to at least one of the top, bottom, edge, or corner of the chemically modified glass substrate structure.

[0033] FIG. 2B is an exemplary block diagram of one embodiment of a method for fabricating a chemically modified glass substrate structure, as shown in FIG. 1B, having one side coated with diamond. In this embodiment, in a first step 212B, at least a first side and a second side of the glass substrate structure are chemically modified using ion substitution. The second side can be either a top, bottom, edge, or corner. In step 212B, CVD diamond is formed on at least the first side. The first side can be either a top, bottom, edge, or corner. In some embodiments, in addition to the first side, additional second, third, or other sides may also be coated with CVD diamond. In step 214B, one or more processing steps, which may include optional additional laminates (e.g., organic, polymer, inorganic, or graphene coatings), can be applied to at least one of the top, bottom, edge, or corner of the chemically modified glass substrate structure.

[0034] FIG. 2C is an exemplary block diagram of one embodiment of a method for fabricating a C-structure, as shown in FIG. 1C, in which at least one surface is diamond-coated. In this embodiment, in a first step 212C, at least a first and a second surface of a glass substrate structure are chemically modified using ion exchange. The second surface can be either a top, bottom, edge, or corner. In step 212C, CVD diamond is formed on at least the first surface. The first surface can be either a top, bottom, edge, or corner. In some embodiments, in addition to the first surface, additional second, third, etc. surfaces may also be coated with CVD diamond. In step 214C, the chemically modified glass substrate structure can be placed in a second or multiple ion exchange baths for further chemical modification. In some embodiments, chemical modification by dopant implantation through the CVD-deposited diamond layer can be used to increase the ion concentration or penetration beneath the diamond. In step 216C, one or more treatment steps, which may include optional additional laminates (such as organic, polymer, inorganic, or graphene coatings), may be applied to at least one of the top, bottom, edge, or corner of the chemically modified glass substrate structure.

[0035] As will be appreciated, various types of glass substrates can be used in the structures. For example, the glass can be a silicate glass, such as alkali silicate glass, soda-lime glass, alkali aluminosilicate glass, aluminosilicate glass, borosilicate glass, alkali aluminogermanate glass, alkali germanate glass, alkali gallogermanate glass, and combinations thereof. The structures can also be fabricated on infrared (IR) substrate materials, such as, but not limited to, silicon (Si), zinc sulfide (ZnS), zinc selenide (ZnSe), germanium (Ge), magnesium fluoride (MGF), sapphire (AlO), aluminum oxynitride (AlON), spinel (MgAlO), calcium fluoride (CaF), and sodium chloride (NaCl). In some embodiments, multiple types of glass or IR materials can be fused or laminated to provide the substrate. Other examples of glass types and compositions suitable for use are described in further detail in U.S. Patent No. 8,232,218, assigned to Corning, Inc.

[0036] The glass substrate can be less than 5 mm thick, and in some embodiments, can have a thickness of 0.5 mm to 3 mm. In particularly thin embodiments, the glass substrate can be 0.3 mm to 1 mm thick. In some embodiments, the glass substrate can be 0.25 mm to 3 mm thick. In other embodiments, the thickness can be less than 2 mm, less than 1 mm, or less than 0.6 mm.

[0037] In one embodiment, the edges of the glass substrate can be formed and chemically modified to correspond to a specific, predetermined shape, thereby enhancing compression near the edges of the glass cover. This can make the glass cover stronger by providing a specific, predetermined shape to the edges of the glass cover. In one embodiment, the surface of the glass cover, for example, the edges, can be chemically modified. In one embodiment, the edge shape is configured to reduce or smooth sharp transitions, such as corners.

[0038] In some embodiments, one or more edges of the glass substrate may be curved or chamfered. A chamfer is a beveled edge that substantially connects two faces or surfaces (e.g., top and bottom surfaces). As an example, the edge shape may include a 0.2-0.5 millimeter chamfered edge that extends at least partially between the top and bottom surfaces of the glass substrate. Advantageously, the use of a chamfered edge can reduce compressive stresses. Alternatively, or in addition, in one embodiment, the edges of the glass substrate may include smooth corners, e.g., no sharp corners between a first surface and a second surface (e.g., a side surface that is substantially perpendicular to the top / bottom surface). As another example, the transition from the top surface to the side surface or between the bottom surface and the side surface may be smooth. In some embodiments, the edges of the glass may be rounded according to a predetermined edge shape, which may have a predetermined edge radius (or predetermined curvature) of at least 10% of the thickness applied to the corner of the glass edge. In other embodiments, the predetermined edge radius can be 20% to 50% of the thickness of the glass. In one embodiment, the glass cover can extend to the edge of the housing of the electronic device without a protective bezel or other barrier. In one embodiment, the glass cover can include a bezel surrounding each edge. The glass cover can be provided on or integrated with a display, such as a liquid crystal display (LCD) that can be used in a smartphone, watch, or tablet.

[0039] In some embodiments, the glass substrate structure may be subjected to optional processing steps. Such processing steps may include applying one or more additional coatings or laminates (e.g., organic, polymer, inorganic, graphene, etc.) to the glass substrate. In some embodiments, the entire substrate may have the additional coating, while in other embodiments, at least one of the top, bottom, edge, or corner of the glass substrate may be provided with a coating.

[0040] In some embodiments, prior to deposition of the diamond or diamond-like coating or film, the substrate can be processed by sputtering, evaporation, atomic layer deposition (ALD), chemical vapor deposition, plasma, or thermal deposition of one or more materials, including, but not limited to, oxide and nitride dielectric materials; oxides of metals such as titanium, indium, tin, and zinc, or combinations thereof; oxides of graphene, such as graphene oxide and reduced fluorinated graphene oxide; oxides, oxynitrides, and nitrides of aluminum, silicon, titanium, or boron; and nitrides of metals such as tungsten or titanium. These intermediate materials can enable or enhance: 1) adhesion of subsequent layers; 2) optical properties of the system, such as transmission and reflection; 3) system stress due to thermal coefficient transitions; 4) reduced surface roughness; and other properties. In some embodiments, for metals deposited by sputter deposition, power levels can be adjusted and shutter opening times can be varied to achieve a uniform target thickness across the display glass surface. For oxides and nitrides, lower temperatures (including temperatures below 600° C.) may be used for thin films. Advantageously, in some embodiments, this reduces differences in thermal expansion coefficients, reduces interlayer and subsurface stresses, and allows for tailoring of color, visual uniformity, and optical losses due to haze or reflectivity.

[0041] Substrates may be seeded with diamond crystal grains to promote the growth of a diamond layer or film at selected grain sizes or in specific regions. Seed layers can be formed through selective deposition or the use of etched seed regions. In some embodiments, nanocrystalline diamond is deposited directly or in solution. In some embodiments, seed sizes can range from 5 nanometers to 50 nanometers. The seeds may be functionalized or have a positive, negative, or neutral zeta potential. The seed crystals may be present in a solvent, dimethyl sulfoxide, oil, photoresist, deionized water, combinations thereof, or similar types of suspensions or matrices. Diamond crystal seed coating on the substrate may be uniformly distributed at 105 to 1013 particles per square centimeter, or may be non-uniformly distributed, or may be locally distributed in selected areas using masks, selective spraying, electrospraying, ultrasonic spraying, sonication, or other spatially localized application formats. In some embodiments, seeds of different sizes and properties may be used.

[0042] In some embodiments, the diamond layer formed on the diamond-sheeted substrate may have an sp2 concentration of less than 20% of the diamond layer volume. In other embodiments, the diamond layer may have at least 80% grain orientation. <111> or <100> In yet another embodiment, the highly oriented diamond film can have, in selected regions or layers, <111> and <100> The crystal orientation may be different, with the crystal orientation of the first order being predominant.

[0043] Diamond properties can be measured and characterized using Raman spectroscopy. Cubic diamond has a single Raman-active first-order phonon mode at the center of the Brillouin zone. The presence of this sharp Raman line allows cubic diamond to be distinguished from a graphitic or other carbon crystalline background. Small shifts in band wavenumber can indicate the composition and properties of diamond. In some embodiments, for diamond layers or films formed as described herein, the full width at half maximum (FWHM) obtained from the Raman signature at 1332 cm-1 may be 5-20 cm-1 for SiN or other suitable buffer layer coated glasses, and 20-85 cm-1 for RIE (reactive ion etched) or other surface treated glasses. In other embodiments, the deposited diamond layer may be measured by Raman analysis to have a relative intensity at 1332 cm-1 compared to the intensity at 1400-1600 cm-1 of 0.5:1 or greater. In other embodiments, the diamond layer may have a physical property such as a Vickers hardness as measured by nanoindentation of at least 12 gigapascals. In other embodiments, the Vickers hardness may be greater than 20 gigapascals. In other embodiments, the diamond layer may be measured to exert a compressive stress of less than 50 gigapascals.

[0044] In some embodiments, a polycrystalline diamond or diamond-like carbon (DLC) coating or material can be formed on the entire substrate or at least a portion of the substrate. In some embodiments, polycrystalline diamond particles with sizes less than 1 micron (1000 nanometers) and greater than 500 nanometers can be used. In other embodiments, the polycrystalline diamond or diamond-like material can include ultrananocrystalline (UNC) particle sizes (2 nanometers to 10 nanometers), nanocrystalline particle sizes (10 nanometers to 500 nanometers), or microcrystalline particle sizes (500 nanometers or greater). In some embodiments, the diamond particle size can include a range of particle sizes, including larger and smaller particles. In some embodiments, the diamond layer can be formed to have particles less than 1 micron. In some embodiments, the particle size can vary by more than 50%, 100%, 200%, or 500% of the average diamond particle size. In other embodiments, the diamond particle size can be maintained within 50%, 20%, or 10% of the average particle size. In some embodiments, 50%, 60%, 80%, or 90% of the diamond particles may be sized between 50 and 500 nanometers. In some embodiments, the diamond layer may be formed from at least 90% nanocrystalline diamond and have diamond particles sized between 2 nanometers and 500 nanometers. In some embodiments, the diamond layer may be formed from at least 90% microcrystalline diamond and have diamond particles sized between 500 nanometers and 1000 nanometers. In other embodiments, the diamond particles may be sized between 500 nanometers and 1000 nanometers. In other embodiments, 90% of the diamond particles may be sized between 200 nanometers and 300 nanometers.

[0045] In some embodiments, the thickness of the diamond layer can be selected between 20 nanometers and 1000 nanometers. Typically, the size of the diamond particles is 50% or less of the thickness of the diamond layer. In some embodiments useful for optical coatings, the thickness of the diamond layer is between 20 nanometers and 500 nanometers. For example, in one embodiment, glass or other transparent material may be coated with a diamond film having a thickness of between 100 nanometers and 300 nanometers.

[0046] The diamond layer may have a substantially uniform thickness across the entire surface or substrate or a predetermined portion thereof. In other embodiments, the thickness may be non-uniform and vary across portions of the surface or substrate. In some embodiments, the diamond layer may be conformal if it extends over cavities, recesses, or protrusions in the substrate or surface. In some embodiments, the diamond layer may gradually thin or thicken with distance from one or more locations on the substrate.

[0047] Multiple diamond layers differentiated by composition, crystal structure, dopant, grain size, or grain size distribution can be part of a multi-layer coating or film system applied to a substrate. Separate diamond layers can be layered on top of diamond or non-diamond materials. In certain embodiments, the physical parameters of the diamond layers can vary continuously or semi-continuously across the layer, either vertically or laterally.

[0048] In certain embodiments, the diamond layer has a thickness of, for example, 30 nanometers to 150 nanometers (e.g., 30 nanometers, 40 nanometers, 50 nanometers, 60 nanometers, 70 nanometers, 80 nanometers, 90 nanometers, 100 nanometers, 110 nanometers, 120 nanometers, 130 nanometers, 140 nanometers, or 150 nanometers, including all ranges and values ​​therebetween). Additionally, the diamond layer can have a root mean square (RMS) surface roughness of less than 2 nanometers.

[0049] Diamond or DLC can be deposited by chemical vapor deposition (CVD), such as hot filament CVD, microwave CVD, radio frequency (rf) CVD, laser CVD (LCVD), or laser ablation, metalorganic CVD (MOCVD), sputtering, thermal evaporation PVD, ionized metal PVD (IMPVD), electron beam PVD (EBPVD), reactive PVD, and cathodic arc deposition. CVD uses a dilute mixture of hydrogen and a carbon-containing gas, such as carbon dioxide or a hydrocarbon, typically methane, whereby the carbon-containing component content typically varies from about 0.1% to 4% of the total volumetric flow. In one of these techniques, the gas mixture is energized using a metal filament, typically electrically heated tungsten, to temperatures ranging from about 170°C to 2400°C. The gas mixture decomposes at the filament surface, and the hybridized carbon in the form of diamond is deposited on a substrate placed below the filament. During operation, the power density at the substrate can be 300-600 W / m² / min. Deposition typically occurs at subatmospheric pressures ranging from 30 mTorr to 300 Torr.

[0050] In some embodiments, thin diamond films can be deposited on substrates having substrate temperatures below 600°C. In other embodiments, deposition can occur at temperatures between 300°C and 600°C. Advantageously, compared to the typical 700°C to 800°C temperatures for conventional CVD diamond film growth, such low temperatures significantly reduce thermal effects, including thermal degradation, stress due to CTE differences, or substrate bowing. Advantageously, this allows for the use of a wider variety of substrates or coatings.

[0051] In some embodiments, various processes can be used to improve the quality of diamond or other films. These processes can be performed, for example, before seeding, before layer deposition, after layer deposition, or after a metrology step that contaminates the surface. For example, the substrate can be subjected to dry and / or wet treatments, including, but not limited to, strong or weak acid and / or base cleaning, solvent cleaning, ultrasonic agitation, plasma cleaning, ultraviolet (UV) light, ozone treatment, application of tetramethylammonium hydroxide, or any other suitable treatment combination. Plasma cleaning can include exposing the substrate to plasma generated from various concentrations of argon and / or oxygen. Post-diamond deposition cleaning processes can be included to clean the substrate and remove unwanted residues deposited during the diamond deposition process, including, for example, solvent cleaning with solvents such as acetone or IPA, and plasma cleaning with O2 / Ar gas using RIE or similar techniques.

[0052] In some embodiments, a glass or other substrate can support multiple thin diamond layers, various intermediate layers, layers pretreated using reactive ion etching (RIE) or other techniques, and a top layer. These can be thin single or multiple layers of metal, ceramic, glass, or other compositions. The thickness of such layers can be less than 1000 nanometers. Such layers can function as capping, intermediate, or buffer layers to improve the optical, electrical, thermal, or mechanical properties of the multilayer structure. In some embodiments, the capping, intermediate, or buffer layer can be transparent and can include one or more of a metal (e.g., tungsten or titanium), a ceramic, a dielectric material, or a glass (e.g., an aluminosilicate or borosilicate). In some embodiments, the capping, intermediate, or buffer layer can include one or more of indium tin oxide, aluminum oxide, oxynitride, titanium oxide, including but not limited to titanium dioxide, magnesium oxide, silicon dioxide, and hafnium oxide. In other embodiments, the cap layer, intermediate layer, or buffer layer can include one or more of aluminum, silicon, titanium, or boron nitride. The cap layer, intermediate layer, or buffer layer can also include, but is not limited to, a carbon film formed from diamond-like carbon (DLC), amorphous carbon, or nanocrystalline diamond (NCD), a metal film formed from molybdenum, titanium, tungsten, chromium, or copper, or a ceramic film formed from SiC, TiC, CrC, WC, BN, B4C, Si3N4, TiN, CrN, SiCN, or BCN. The thickness of the cap layer, intermediate layer, or buffer layer can range from 2 nanometers to 1000 nanometers.

[0053] In some embodiments, the deposited diamond film can be cleaned and exposed to a two-dimensional top layer material, such as reduced fluorinated graphene oxide, graphene, graphene oxide, or f-silane. In some embodiments, this results in superhydrophobic or oleophobic properties without significantly degrading the diamond film's properties, including optical transmittance and / or hardness. In one embodiment, graphene oxide can be derived from a chemical suspension of multilayer graphene oxide, spin-coated onto the diamond film, and then wet-chemically or dry-chemically (plasma-) reduced in place of oxygen through the introduction of fluorine atoms into the material.

[0054] In some embodiments, the substrate and / or diamond layer may be subjected to a surface functionalization process, which may include spray coating, biased spray coating, ultrasonic spray coating, or wet chemical surface functionalization using ultrasonic agitation of solvents and ketone mixtures (including, but not limited to, methanol, acetone, isopropyl alcohol, ethanol, butanol, and pentanol). The functionalized surface may include hydrocarbon chains, hydroxyl bonds, oxygen end groups, or other suitable chemically active materials.

[0055] In some embodiments, the substrate and / or diamond layer may be subjected to a surface functionalization process, which may include spray coating, bias spray coating, ultrasonic spray coating, or wet chemistry surface functionalization using ultrasonic agitation of a solvent and ketone mixture (including, but not limited to, methanol, acetone, isopropyl alcohol, ethanol, butanol, and pentanol). The functionalized surface may include hydrocarbon chains, hydroxyl bonds, oxygen end groups, or other suitable chemically active materials.

[0056] In some embodiments, the single or multiple diamond layers or films can include additional multilayer structures that enable or enhance various applications or functions, including those that provide light redirection, interference, cover glass, protective covers, displays, windows, chemical, thermal, or mechanical protection. Applications or components that use multilayer diamond layers, films, or coatings can include, but are not limited to, visible or infrared optics, windows, optical waveguides, semiconductors, semiconductor coatings, and robust or durable coatings for electronics, manufacturing equipment, or tooling. Other applications for diamond multilayer coatings include use in biological substrates or medical devices, or integration with batteries, fuel cells, electrochemical systems, chemical sensors, general-purpose sensing devices, or other advanced materials.

[0057] As will be appreciated, the described diamond layers, substrates, and thin films of non-diamond material can include a variety of embodiments, properties, and combinations, including but not limited to the following additional examples. [Example]

[0058] In a first example, a multilayer transparent diamond structure comprising nanocrystalline and ultrananocrystalline diamond layers can be continuously and conformally coated onto a transparent glass substrate to serve as an optically transparent protective coating suitable for smartphones, tablets, or laptops. For example, a nanocrystalline diamond film of substantially uniform thickness between 70 nanometers and 110 nanometers, with a grain size ranging from 20 nanometers to 70 nanometers, can be deposited on a conductive indium tin oxide (ITO) film deposited on a transparent glass substrate. In some embodiments, an ultrananocrystalline diamond layer having a grain size between 2 nanometers and 10 nanometers and a thickness between 20 nanometers and 500 nanometers can be deposited on the nanocrystalline diamond layer. In some embodiments, the ultrananocrystalline diamond layer can have a diamond grain size between 2 nanometers and 10 nanometers and a thickness between 20 nanometers and 200 nanometers. In some embodiments, the ultrananocrystalline diamond layer can have a thickness of less than 50 nanometers, with at least 50% of the ultrananocrystalline diamond grains having a grain size between 2 nanometers and 10 nanometers. Optionally, an additional diamond coating doped or functionalized to support a hydrophobic or oleophobic coating can be deposited on the ultrananocrystalline diamond layer. The glass substrate can be chemically cleaned with acetone followed by UV ozone cleaning. Alternatively, float glass or similar substrates can be acid washed to remove tin or other metal coatings. In some embodiments, the glass surface can be functionalized by introducing hydrocarbon chains onto the glass surface, which are generated by decomposition of the solvent during drying.

[0059] Conventional HFCVD reactors with tungsten, tantalum, or rhenium filaments can be used. The diameter, spacing, and number of filaments can be adjusted to achieve optimal results. In one embodiment, the filament diameter can be 0.12-0.5 mm, the spacing can be 8-30 mm, and 7-28 filaments can be used. The chamber can be spherical, rectangular, or cylindrical. In one embodiment, a cylindrical sphere can be sized to have a diameter of 30-150 centimeters and a volume of 100-200 liters.

[0060] The reactor may include stages to assist in heating or cooling the substrate. In some embodiments, the reactor stages may be configured to provide a substrate deposition temperature of 500-600°C. At this temperature range, the deposition rate of the diamond layer may be 10-100 nanometers per hour.

[0061] Precursor gases such as methane, hydrogen, oxygen, and argon can be introduced into the chamber at pressures of 10 to 15 Torr. Adding less than 1% oxygen can lower the temperature required to maintain the expected deposition rate, and oxygen preferentially etches sp2 deposition regions. The methane concentration can be 0.5 to 5% of the total gas volume. The hydrogen concentration can be 60 to 90% of the total gas volume. The argon concentration can be 10 to 40% of the total gas volume.

[0062] To ensure uniform particle size, the substrate can be coated with diamond seeds dispersed in dimethyl sulfoxide (DMSO) or other solvent solutions, including but not limited to ethanol, methanol, IPA, and acetone. In some embodiments, particle sizes between 5 nanometers and 50 nanometers can be used.

[0063] In some embodiments, the diamond film is continuous and conformal on the substrate.

[0064] Furthermore, the diamond film has a full width at half maximum (FWHM) of 5-7, an sp2 concentration of less than 20% by volume, <111> The diamond film may have at least 80% grain orientation in the crystallographic direction, a diamond Raman spectrum (approximately 1332 nm) of 0.7:1 to 1.2:1 when compared to the peak graphite band (1400 nm to 1600 nm), and a Vickers hardness of 20 to 60 gigapascals. The transmittance of light at a wavelength of 550 nanometers through the glass substrate and diamond film is greater than 0.70, and the haze is less than 5%. [Example]

[0065] In a second example, a substrate can be coated with a nanocrystalline diamond layer or film of substantially uniform thickness between 100 nanometers and 2000 nanometers, with a grain size ranging from 100 nanometers to 2000 nanometers, and a thicker ultra-nanocrystalline diamond layer. In some embodiments, an optional ultra-nanocrystalline diamond layer of 20 nanometers to 200 nanometers thickness can be deposited with a grain size between 2 nanometers and 10 nanometers. In some embodiments, the ultra-nanocrystalline diamond layer can have a thickness of less than 50 nanometers, with at least 50% of the ultra-nanocrystalline diamond grains being sized between 2 nanometers and 10 nanometers. In one embodiment, the nanocrystalline diamond film of 100 nanometers to 2000 nanometers thick and the optional covering ultra-nanocrystalline diamond layer can be further etched, and additional layers or films can be selectively applied to fill the etched diamond and support the formation of waveguides for data transmission. In some embodiments, the deposited grain size can include diamond grains in the range of 5 nanometers to 50 nanometers. The reactor can include a stage to support heating or cooling of the substrate. In some embodiments, the reactor stage can be set to provide a substrate deposition temperature of between 500° C. and 800° C. In this temperature range, the deposition rate of the diamond layer can be between 10 nanometers and 200 nanometers per hour, while in other embodiments, it can be less than 10 nm per hour.

[0066] The substrate can be coated with diamond seeds dispersed in DMSO or other solvent solutions, including, but not limited to, ethanol, methanol, IPA, and acetone. In some embodiments, particle sizes between 5 nanometers and 15,000 nanometers can be used, with larger particle sizes typically being pulverized by sonication or other processing steps. In some embodiments, various particle sizes or particle size ranges can be used, including co-deposition of small and large particle sizes. In some embodiments, the seeds are deposited to ensure a continuous and conformal film across the substrate.

[0067] In some embodiments, the diamond layer or film may have a Young's modulus greater than 80 gigapascals. [Example]

[0068] In a third example, the substrate can be coated with multiple layers, including diamond, ceramic, or metal layers. In some embodiments, a nanocrystalline diamond layer or film can be deposited with a substantially uniform thickness of 5 nanometers to 50 nanometers, with a grain size in the range of 5 nanometers to 50 nanometers. In some embodiments, an optional ultrananocrystalline diamond layer can be deposited with a grain size of 2 nanometers to 10 nanometers and a thickness of 20 nanometers to 200 nanometers. In some embodiments, the optional ultrananocrystalline diamond layer can have a thickness of less than 50 nanometers, with at least 50% of the ultrananocrystalline diamond grains being sized between 2 nanometers and 10 nanometers.

[0069] The reactor may include stages to assist in heating or cooling the substrate. In some embodiments, the reactor stages may be configured to provide a substrate deposition temperature of 500-600°C. At this temperature range, the deposition rate of the diamond layer may be 10-100 nanometers per hour.

[0070] In the foregoing description, reference has been made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific exemplary embodiments in which the present disclosure may be practiced. These embodiments have been described in sufficient detail to enable those skilled in the art to practice the concepts disclosed herein, and it will be understood that changes can be made in the various disclosed embodiments and other embodiments can be utilized without departing from the scope of the present disclosure. Accordingly, the foregoing detailed description is not to be construed in a limiting sense.

[0071] References throughout this specification to "one embodiment," "embodiment," "one example," or "example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one embodiment," "in an embodiment," "one example," or "example" in various places throughout this specification do not necessarily all refer to the same embodiment or example. Furthermore, particular features, structures, databases, or characteristics may be combined in any suitable combination and / or subcombination in one or more embodiments or examples. Also, please note that the figures provided herein are for illustrative purposes to persons skilled in the art, and that these figures are not necessarily drawn to scale.

[0072] Various modifications and other embodiments of the present invention will occur to those skilled in the art based on the teachings presented in the above description and its associated drawings. It is therefore understood that the present invention is not limited to the specific embodiments disclosed, but that modifications and embodiments are intended to be included within the scope of the appended claims. It is also understood that other embodiments of the present invention may be practiced in the absence of elements / steps not specifically disclosed herein.

Claims

1. 1. A diamond-coated glass structure comprising: a glass substrate having a first surface and a second surface, the second surface being chemically modified by ion substitution; a CVD deposited diamond layer on said first surface; A structure having:

2. 10. The structure of claim 1, wherein the CVD deposited diamond layer has less than 20% SP2 carbon.

3. 10. The structure of claim 1, wherein the CVD deposited diamond layer comprises multiple diamond layers.

4. 10. The structure of claim 1, wherein the CVD deposited diamond layer comprises a layer of ultrananocrystalline diamond on a layer of nanocrystalline diamond.

5. 10. The structure of claim 1, wherein the substrate has a dimension of at least one centimeter.

6. 10. The structure of claim 1, wherein the ion substitution further comprises replacing at least a portion of the sodium ions with potassium ions.

7. 10. The structure of claim 1, wherein ion substitution further comprises replacing at least some ions on the second surface to a penetration depth of less than 100 microns.

8. 1. A diamond-coated glass structure comprising: a glass substrate having a first surface and a second surface, the first surface and the second surface being chemically modified by ion substitution, and the penetration depths of the first surface and the second surface being different from each other; a CVD deposited diamond layer on at least one of the first and second surfaces; A structure having:

9. 9. The structure of claim 8, wherein the CVD deposited diamond layer comprises multiple diamond layers.

10. 9. The structure of claim 8, wherein the CVD deposited diamond layer comprises a layer of ultrananocrystalline diamond on a layer of nanocrystalline diamond.

11. 9. The structure of claim 8, wherein the ion substitution further comprises replacing at least a portion of the sodium ions with potassium ions.

12. 9. The structure of claim 8, wherein ion substitution further comprises substituting at least some ions on the second surface to a penetration depth of less than 100 microns.

13. 1. A diamond-coated glass structure comprising: A glass substrate having opposing first and second surfaces and four edges, wherein the first and second surfaces and the four edges are chemically modified by ion substitution, and the penetration depth of the first surface is different from that of the second surface and at least one of the four edges; a CVD deposited diamond layer on said first surface; A structure having:

14. 14. The structure of claim 13, wherein the CVD deposited diamond layer comprises multiple diamond layers.

15. 14. The structure of claim 13, wherein the CVD deposited diamond layer comprises a layer of ultrananocrystalline diamond on a layer of nanocrystalline diamond.

16. 14. The structure of claim 13, wherein the substrate has a dimension of at least one centimeter.

17. 14. The structure of claim 13, wherein the ion substitution further comprises replacing at least a portion of the sodium ions with potassium ions.

18. 14. The structure of claim 13, wherein ion substitution further comprises replacing at least some ions on the second surface to a penetration depth of less than 100 microns.

19. 1. A method of forming a diamond-coated glass structure, comprising: providing a glass substrate having a first side and a second side; CVD depositing a diamond layer on the first surface; chemically modifying said second surface by ion substitution after CVD diamond deposition; A method having the following.

20. 20. The method of forming a diamond-coated glass structure of claim 19, wherein the first surface of the glass substrate is chemically modified.

21. 1. A method of forming a diamond-coated glass structure, comprising: providing a glass substrate having a first side and a second side; chemically modifying the first surface and the second surface a first time by ion substitution; CVD depositing a diamond layer on the first surface; chemically modifying both the first and second surfaces by ion substitution a second time after CVD diamond deposition; A method comprising:

22. 1. A method of forming a diamond-coated glass structure, comprising: providing a glass substrate having a first side and a second side; chemically modifying the first surface and the second surface a first time by ion substitution; CVD depositing a diamond layer on the first surface; chemically modifying only the second surface by ion substitution for a second time after CVD diamond deposition; A method having the following.

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